LM2576T-ADJ/NOPB National Semiconductor, LM2576T-ADJ/NOPB Datasheet - Page 6
Manufacturer Part Number
IC REG SIMPLE SWITCHER TO-220-5
Specifications of LM2576T-ADJ/NOPB
Number Of Outputs
Voltage - Output
1.23 ~ 37 V
Current - Output
Frequency - Switching
Voltage - Input
4 ~ 40 V
-40°C ~ 125°C
Package / Case
TO-220-5 (Straight Leads)
Current, Input Bias
Resistance, Thermal, Junction To Case
Temperature, Operating, Range
-40 to +125 °C
1.23 to 37 V
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Power - Output
Lead Free Status / Rohs Status
RoHS Compliant part Electrostatic Device
ON /OFF CONTROL Test Circuit Figure 2
All Output Voltage Versions
Specifications with standard type face are for T
Range. Unless otherwise specified, V
= 30V for the 15V version. I
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.
Note 2: All limits guaranteed at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits are 100%
production tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) methods.
Note 3: External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance. When the
LM2576/LM2576HV is used as shown in the Figure 2 test circuit, system performance will be as shown in system parameters section of Electrical Characteristics.
Note 4: Output pin sourcing current. No diode, inductor or capacitor connected to output.
Note 5: Feedback pin removed from output and connected to 0V.
Note 6: Feedback pin removed from output and connected to +12V for the Adjustable, 3.3V, and 5V versions, and +25V for the 12V and 15V versions, to force the
output transistor OFF.
Note 7: V
Note 8: Junction to ambient thermal resistance (no external heat sink) for the 5 lead TO-220 package mounted vertically, with
board with minimum copper area.
Note 9: Junction to ambient thermal resistance (no external heat sink) for the 5 lead TO-220 package mounted vertically, with
containing approximately 4 square inches of copper area surrounding the leads.
Note 10: If the TO-263 package is used, the thermal resistance can be reduced by increasing the PC board copper area thermally connected to the package. Using
0.5 square inches of copper area, θ
Note 11: The oscillator frequency reduces to approximately 11 kHz in the event of an output short or an overload which causes the regulated output voltage to drop
approximately 40% from the nominal output voltage. This self protection feature lowers the average power dissipation of the IC by lowering the minimum duty cycle
from 5% down to approximately 2%.
Typical Performance Characteristics
(Circuit of Figure 2)
= 40V (60V for high voltage version).
ON /OFF Pin
Logic Input Level
ON /OFF Pin Input
Normalized Output Voltage
is 50˚C/W, with 1 square inch of copper area, θ
= 500 mA.
= 12V for the 3.3V, 5V, and Adjustable version, V
T Package, Junction to Ambient (Note 8)
T Package, Junction to Ambient (Note 9)
T Package, Junction to Case
S Package, Junction to Ambient (Note 10)
ON /OFF Pin = 5V (OFF)
ON /OFF Pin = 0V (ON)
= Nominal Output Voltage
= 25˚C, and those with boldface type apply over full Operating Temperature
is 37˚C/W, and with 1.6 or more square inches of copper area, θ
= 25V for the 12V version, and V
inch leads soldered to a PC board
inch leads in a socket, or on a PC